Historic Churches 2022

30 BCD SPECIAL REPORT ON HISTORIC CHURCHES 29TH ANNUAL EDITION degrees. All were successfully conserved and will tell the history of the church for many generations to come. STONEWORK CONSERVATION The fire was concentrated in the tower but it also travelled to the nave via the arch which connects the two. Due to its location, the stone arch sustained an extreme amount of heat from the fire which significantly affected its structural integrity, and large sections were now fractured, brittle and spalling away. As a result, it was necessary to replace the complete intrados and extrados (tower side only) of the moulded arch, spanning a massive five meters. Ancaster Hard White was found to provide a suitable match for the existing stone. Following a detailed survey, Bakers of Danbury’s sister company, Collins and Curtis Masonry Ltd produced the individual arch voussoirs in their masons’ workshops in Ipswich, using measurements from the original fire damaged arch. To help install them correctly, a full-size timber former was constructed within the arch, and then removed when the last voussoir was slotted into place. The surviving stones of the arch were then cleaned using the DOFF method to ensure the new replacement Ancaster stone blended in. After a number of cleaning trials, the DOFF method was also used to gently clean the stone columns within the nave, the belfry openings to the tower and all external stone and flint walls on the tower. DOFF was chosen because it enables control of the water pressure and temperature used, which helps prevent overcleaning the surface. This was particularly important when cleaning the external stone and flint on the tower as the team did not want to remove the underlying patina (the natural variations in colour and texture which develop over many years of weathering). Dry ice blast cleaning techniques were carried out in other isolated areas of the church which suffered fire and smoke damage, for example around the stone windows, doors and arches. Bakers of Danbury’s team carried out extensive repairs to the internal walls of the tower, particularly at the belfry level where it had been damaged by the intense heat and by the large volumes of water used to extinguish the fire. Tottenhoe was sourced to match the original clunch (a chalky form of limestone) and used to replace the inner jambs to all ten of the lancet-arched openings to the tower. This required around 300 new shaped jamb stones and all new Welsh slate louvres. Repairs to the interior of the tower required over 500 new ashlar stones and the walls had to be completely re-pointed using lime mortar. Large structural fractures found when the plaster was fully removed were stitched with large pieces of stone, and the walls finally covered with limewash. A stone quatrefoil window was replaced using Ancaster Hard White stone and new merlon copings (the uppermost copings on a crenellated parapet) produced from Barnack Stone were installed to the tower parapets. Lower sections to the moulded stone columns to the nave arcade, also affected by the fire and water damage, were carefully replicated and replaced using Chicksgrove stone as the best match for the original. CONSERVATION OF FRAGMENTS MEDIEVAL WALL PAINTINGS All fire- and water-damaged plaster was removed, and the walls were re-plastered with a breathable three-coat lime plaster (coarse hair coat, scratch coat and fine finish coat). Further from the seat of the fire the walls did not look too bad, but the surfaces retained an oily residue from the smoke which a traditional limewash would not have adhered to. Both old and new plastered surfaces were therefore finished with Zinsser Grade 1*, a highly breathable modern paint system which was found to adhere well to surfaces contaminated by smoke deposits. This was tinted to a suitable colour. As the damaged plaster was being removed from the south wall of the north aisle, fragments of historic painted decoration were revealed in the spaces between arches. At the request of the property consultants, wall paintings specialists Tobit Curteis Associates were brought in to undertake an initial inspection of the painted decoration and to make recommendations for its protection and conservation. The painting was limited to specific blocks of clunch and in all cases the scheme was found to have been painted directly onto the blocks – indicating that the decorated limestone blocks had been reused from an area once covered by a large-scale scheme of decoration. The painting is obscured by post medieval limewash residues remaining on the surface. The paintings consist of a foliate background and elaborate gilded floral decoration. The white ground may be white lead covered with multiple layers of dense pigment in an organic medium, possibly oil, and are likely to include red Cracked and spalling masonry in the tower caused by the cooling effects of water from the fire hoses when fighting the fire A new quatrefoil window surround carved from Ancaster Hard White stone *According to the manufacturer, Zinsser Grade 1 is based on a speciality resin which allows very high pigmentation of the paint while still ‘binding’ it together. The pigment volume of the dry film is in excess of 70%. This makes it extremely breathable as there are micro voids and pathways for water vapour to pass through, but not large enough for liquid water to pass. The pigments are calcium carbonate, talc and titanium dioxide, all micronised.